OMTEX CLASSES: 10th Science Quarterly Exam Question Paper 2023 with Solutions

10th Science Quarterly Exam Question Paper 2023 with Solutions | Virudhunagar District

This post contains the fully solved question paper for the Standard 10 Science Common Quarterly Examination conducted in Virudhunagar District in 2023. Students can use this as a reference for exam preparation and to understand the question pattern and marking scheme.

PART - I (Marks: 12x1=12)

Note: i) Answer all the questions. ii) Choose the correct answers.

One Kilogram force equals to
a) 9.8 dyne b) 9.8 x 10⁵ N c) 98 x 10⁴ dyne d) 980 dyne
Answer: c) 98 x 10⁴ dyne (Since 1 kgf = 9.8 N, and 1 N = 10⁵ dyne, so 1 kgf = 9.8 x 10⁵ dyne. 98 x 10⁴ dyne is equivalent to 9.8 x 10⁵ dyne.)
The eye defect 'presbyopia' can be corrected by
a) convex lens b) concave lens c) convex mirror d) Bifocal lenses
Answer: d) Bifocal lenses
If a substance is heated or cooled, the change in mass of that substance is
a) Positive b) negative c) zero d) None of the above
Answer: c) zero
SI unit of resistance is
a) mho b) joule c) ohm d) ohm meter
Answer: c) ohm
Which one is making Electromagnet?
a) Pig Iron b) Wrought iron c) Steel d) None of the above
Answer: a) Pig Iron (Soft iron)
Which of the following is the universal solvent?
a) Acetone b) Benzone c) Water d) Alcohol
Answer: c) Water
Which is formed during anaerobic respiration
a) Carbohydrate b) Ethyl alcohol c) Acetyl Co A d) Pyruvate
Answer: b) Ethyl alcohol
Which device is used to measure blood pressure
a) stethoscope b) sphygmomanometer c) Animometer d) Hydrometer
Answer: b) sphygmomanometer
Bipolar neurons are found in
a) retina of eye b) cerebral cortex c) embryo d) respiratory epithelium
Answer: a) retina of eye
Which one is referred as "Master Gland"?
a) Pineal gland b) pituitary gland c) Thyroid gland d) Adrenal gland
Answer: b) pituitary gland
Syngamy results in the formation of
a) zoospores b) conidia c) Zygote d) chlamydospores
Answer: c) Zygote
The father of Genetics is ..........
a) Landsteiner b) Gregor Johann Mendel c) William Harvey d) Charles Darwin
Answer: b) Gregor Johann Mendel

PART - II (Marks: 7x2=14)

Note: Answer any 7 questions. (Q.No. 22 is compulsory)

13) Differentiate mass and weight.

Mass	Weight
It is the quantity of matter contained in an object.	It is the gravitational force exerted on an object by the Earth.
It is a fundamental quantity.	It is a derived quantity.
Its SI unit is kilogram (kg).	Its SI unit is newton (N).
It remains the same everywhere.	It varies from place to place.

14) What is power of accommodation of eye?

The ability of the eye lens to focus nearby as well as distant objects by adjusting its focal length is called the power of accommodation of the eye. This is achieved by the ciliary muscles changing the curvature of the lens.

15) Match:

i) Linear expansion - a) hot body to cold body
ii) Cubical expansion - b) 1.381 ×10⁻²³ JK⁻¹
iii) Heat transformation - c) Change in length
iv) Boltzmann constant - d) Change in volume

Correct Matches:

i) Linear expansion - c) Change in length
ii) Cubical expansion - d) Change in volume
iii) Heat transformation - a) hot body to cold body
iv) Boltzmann constant - b) 1.381 ×10⁻²³ JK⁻¹

16) State Ohm's law.

Ohm's law states that at a constant temperature, the steady current (I) flowing through a conductor is directly proportional to the potential difference (V) between its ends.
Mathematically, V ∝ I, or V = IR, where R is the constant of proportionality called resistance.

17) What is rust? Give the equation for formation of rust.

Rust is a hydrated ferric oxide (Fe₂O₃·xH₂O) which is formed when iron is exposed to moist air (oxygen and water). It is a reddish-brown flaky substance that forms on the surface of iron.
Equation: 4Fe + 3O₂ + xH₂O → 2Fe₂O₃·xH₂O (Hydrated ferric oxide - Rust)

18) What is respiratory quotient?

Respiratory Quotient (RQ) is the ratio of the volume of carbon dioxide evolved to the volume of oxygen consumed during respiration.
RQ = Volume of CO₂ liberated / Volume of O₂ consumed

19) Why is the Sinoatrial node called the pacemaker of heart?

The Sinoatrial (SA) node is called the pacemaker of the heart because it has the ability to generate nerve impulses that travel through the heart wall, causing the heart muscles to contract. It initiates and maintains the rhythmic contraction of the heart.

20) Differentiate between voluntary and involuntary actions.

Voluntary Actions	Involuntary Actions
Actions performed under our conscious control.	Actions that occur without our conscious control.
Controlled by the cerebrum.	Controlled by the medulla oblongata and spinal cord.
Example: Walking, writing, eating.	Example: Heartbeat, breathing, digestion.

21) Why did Mendel select pea plant for his experiments?

Mendel selected the pea plant (Pisum sativum) for his experiments due to the following reasons:

It is naturally self-pollinating and can also be cross-pollinated.
It has a short life span and produces many offspring.
It has several pairs of easily distinguishable contrasting characters (e.g., tall/dwarf, round/wrinkled seeds).

22) (Compulsory) Calculate the current and the resistance of a 100W, 200V electric bulb in an electric circuit.

Given: Power (P) = 100 W, Voltage (V) = 200 V
i) To find Current (I):
We know, P = V × I
I = P / V = 100 W / 200 V = 0.5 A
ii) To find Resistance (R):
From Ohm's Law, V = I × R
R = V / I = 200 V / 0.5 A = 400 Ω

PART - III (Marks: 7x4=28)

Note: Answer any 7 questions. (Q.No. 32 is compulsory)

23) Describe rocket propulsion.

Rocket propulsion is based on the law of conservation of linear momentum and Newton's third law of motion.

In a rocket, fuel is burnt in the combustion chamber, producing a large quantity of hot gas.
These gases are ejected with very high velocity through a nozzle at the back of the rocket.
According to Newton's third law, for every action (gases being ejected backward), there is an equal and opposite reaction.
This reaction force is the upward thrust that propels the rocket forward.
Although the mass of the gas ejected is small, its extremely high velocity results in a large momentum. To conserve the total momentum of the system (rocket + gas), the rocket moves forward with a large velocity.

24) Differentiate the eye defects: Myopia and Hypermetropia.

Feature	Myopia (Near-sightedness)	Hypermetropia (Far-sightedness)
Vision	Can see nearby objects clearly, but distant objects appear blurry.	Can see distant objects clearly, but nearby objects appear blurry.
Cause	Eyeball is too long, or focal length of the eye lens is too short.	Eyeball is too short, or focal length of the eye lens is too long.
Image Formation	Image of a distant object is formed in front of the retina.	Image of a nearby object is formed behind the retina.
Correction	Corrected using a concave lens of appropriate power.	Corrected using a convex lens of appropriate power.

25) i) Distinguish between the resistivity and conductivity of a conductor. ii) Name any two devices, which are working on the heating effect of the electric current.

i) Distinction between Resistivity and Conductivity:

Resistivity (ρ)	Conductivity (σ)
It is the resistance of a conductor of unit length and unit area of cross-section.	It is the reciprocal of resistivity. It measures how well a material conducts electricity.
SI unit is Ohm-meter (Ω m).	SI unit is Siemens per meter (S/m) or mho/m.
Formula: ρ = RA/L	Formula: σ = 1/ρ

ii) Devices working on the heating effect of electric current:

Electric Heater
Electric Iron Box
Fuse Wire

26) Explain the methods of preventing corrosion.

Corrosion can be prevented by the following methods:

Painting: Applying a coat of paint on the metal surface cuts off the contact between the metal and the environment (air, moisture).
Galvanization: It is the process of coating iron or steel with a thin layer of zinc. Zinc is more reactive than iron and gets corroded first, thus protecting the iron. This is a form of sacrificial protection.
Electroplating: It involves coating a metal with a thin layer of another metal (like chromium, nickel, tin) using electrolysis. This not only prevents corrosion but also improves the appearance.
Anodizing: It is an electrochemical process that converts the metal surface into a decorative, durable, corrosion-resistant, anodic oxide finish. It is commonly used for aluminum.
Cathodic Protection: The metal to be protected is made the cathode and a more reactive metal is made the anode. The anode metal corrodes sacrificially, protecting the cathode.

27) Write notes on i) Saturated solution ii) Unsaturated solution

i) Saturated solution:
A saturated solution is a solution that contains the maximum amount of solute that can be dissolved in a given amount of solvent at a specific temperature. If more solute is added to a saturated solution, it will not dissolve and will settle at the bottom.

ii) Unsaturated solution:
An unsaturated solution is a solution that contains less solute than the maximum amount that can be dissolved in a given amount of solvent at a specific temperature. It has the capacity to dissolve more solute.

28) Describe and name three stages of cellular respiration that aerobic organisms use to obtain energy from glucose.

The three main stages of aerobic cellular respiration are:

Glycolysis: This is the initial stage, occurring in the cytoplasm. One molecule of glucose (a 6-carbon compound) is broken down into two molecules of pyruvic acid (a 3-carbon compound). This process does not require oxygen and produces a net gain of 2 ATP and 2 NADH.
Krebs Cycle (Citric Acid Cycle): This stage occurs in the mitochondrial matrix. The pyruvic acid from glycolysis is first converted to Acetyl-CoA, which then enters the Krebs cycle. Through a series of reactions, it is completely oxidized, releasing carbon dioxide, ATP, NADH, and FADH₂.
Electron Transport Chain (ETC): This is the final stage, occurring on the inner mitochondrial membrane. The high-energy electrons from NADH and FADH₂ (produced in the previous stages) are passed along a series of protein carriers. This process releases a large amount of energy, which is used to synthesize a significant number of ATP molecules. Oxygen acts as the final electron acceptor, forming water.

29) i) Enumerate the functions of blood. (Any two) ii) What are the structures involved in the protection of brain?

i) Functions of Blood (Any two):

Transport: Transports respiratory gases (oxygen and carbon dioxide), nutrients (glucose, amino acids), hormones, and waste products.
Protection: White blood cells (leukocytes) defend the body against pathogens. Platelets are involved in blood clotting to prevent excessive blood loss.
Regulation: Helps in regulating body temperature, pH, and water balance.

ii) Structures involved in the protection of the brain: The brain is protected by:

Cranium (Skull): The bony box that encloses the brain.
Meninges: Three protective membranes that lie between the skull and the brain. They are the outer Dura mater, the middle Arachnoid membrane, and the inner Pia mater.
Cerebrospinal Fluid (CSF): A fluid found in the space between the meninges (subarachnoid space) and in the ventricles of the brain. It acts as a shock absorber, protecting the brain from mechanical injury.

30) Write the physiological effects of gibberellins.

The physiological effects of gibberellins in plants include:

Promoting extraordinary elongation of internodes, as seen in "bolting" of rosette plants like cabbage.
Breaking the dormancy of buds and seeds.
Inducing the formation of male flowers in some dioecious plants.
Promoting the production of seedless fruits (parthenocarpy), for example, in grapes.
Delaying senescence (aging) in plants.

31) i) What is colostrum? ii) What are Okazaki fragment?

i) Colostrum:
Colostrum is the first form of milk produced by the mammary glands of mammals immediately following delivery of the newborn. It is thick, yellowish, and rich in proteins and antibodies (especially IgA), which provide passive immunity to the baby, protecting it from infections.

ii) Okazaki fragment:
Okazaki fragments are short, newly synthesized DNA fragments that are formed on the lagging strand during DNA replication. Because DNA polymerase can only synthesize DNA in the 5' to 3' direction, the lagging strand is synthesized discontinuously in small pieces. These fragments are later joined together by the enzyme DNA ligase to form a continuous strand.

32) (Compulsory) A solution is prepared by dissolving 45g of sugar in 180g of water. Calculate the mass percentage of solute.

Given:

Mass of solute (sugar) = 45 g
Mass of solvent (water) = 180 g

Step 1: Calculate the mass of the solution.
Mass of solution = Mass of solute + Mass of solvent
Mass of solution = 45 g + 180 g = 225 g

Step 2: Calculate the mass percentage of the solute.
Mass percentage of solute = (Mass of solute / Mass of solution) × 100
Mass percentage = (45 g / 225 g) × 100
Mass percentage = (1 / 5) × 100
Mass percentage = 20%

PART - IV (Marks: 3x7=21)

Note: Answer all questions. Each question carries seven marks. (Draw diagram wherever necessary)

33) i) State and prove the law of conservation of linear momentum. ii) Define dispersion of light.

i) Law of Conservation of Linear Momentum:
Statement: In the absence of any external unbalanced force, the total linear momentum of a system of interacting objects remains constant.
Proof: Consider two bodies, A and B, of masses m₁ and m₂ moving with initial velocities u₁ and u₂ in a straight line. Let u₁ > u₂. They collide for a time 't'. After collision, their velocities change to v₁ and v₂ respectively.
Force on body B by A (Action), Fₐ = m₂(v₂ - u₂)/t
Force on body A by B (Reaction), Fₙ = m₁(v₁ - u₁)/t
According to Newton's third law of motion, Action = -Reaction
Fₐ = -Fₙ
m₂(v₂ - u₂)/t = -[m₁(v₁ - u₁)/t]
m₂(v₂ - u₂) = -m₁(v₁ - u₁)
m₂v₂ - m₂u₂ = -m₁v₁ + m₁u₁
Rearranging the terms, we get:
m₁v₁ + m₂v₂ = m₁u₁ + m₂u₂
This shows that the total momentum after collision is equal to the total momentum before collision, provided no external force acts on the system. Hence, the law is proved.

ii) Dispersion of light:
Dispersion of light is the phenomenon of splitting of a beam of white light into its seven constituent colors (VIBGYOR - Violet, Indigo, Blue, Green, Yellow, Orange, Red) when it passes through a transparent medium like a glass prism. This occurs because the refractive index of the medium is different for different wavelengths (colors) of light.

(OR)

i) State Joule's law of heating. ii) An alloy of nickel and chromium is used as the heating element. Why? iii) How does a fuse wire protect electrical appliances?

i) Joule's Law of Heating:
The law states that the heat (H) produced in a conductor is directly proportional to:

the square of the current (I²) flowing through it,
the resistance (R) of the conductor, and
the time (t) for which the current flows.

Mathematically, H = I²Rt. The SI unit of heat produced is Joule (J).

ii) Why an alloy of nickel and chromium (Nichrome) is used as a heating element:
Nichrome is used as a heating element because it possesses:

High Resistivity: It offers high resistance to the flow of current, thus producing a large amount of heat.
High Melting Point: It can withstand very high temperatures without melting.
Resistance to Oxidation: It does not easily oxidize (burn) even when red-hot, which increases its lifespan.

iii) How a fuse wire protects electrical appliances:
A fuse wire is a safety device made of a material with a low melting point. It is connected in series with the main circuit. When an excessive current (due to short-circuiting or overloading) flows through the circuit, the fuse wire heats up quickly according to Joule's law (H ∝ I²). Since its melting point is low, it melts and breaks the circuit. This stops the flow of current, thereby protecting the expensive electrical appliances from damage.

34) i) Give the salient features of "Modern atomic theory". ii) State Avogadro's law.

i) Salient Features of Modern Atomic Theory:

The atom is no longer considered indivisible. It is made up of subatomic particles: protons, neutrons, and electrons.
Atoms of the same element may have different atomic masses. These are called isotopes (e.g., ¹²C, ¹³C, ¹⁴C).
Atoms of different elements may have the same atomic mass. These are called isobars (e.g., ⁴⁰Ar, ⁴⁰K, ⁴⁰Ca).
Atoms are not always indestructible. They can be transformed into atoms of other elements through nuclear reactions (transmutation).
The mass of an atom can be converted into energy according to Einstein's equation, E=mc².
Atoms may not always combine in simple whole-number ratios. For example, in sucrose (C₁₂H₂₂O₁₁), the ratio is 12:22:11.

ii) Avogadro's Law:
Avogadro's law states that equal volumes of all gases under the same conditions of temperature and pressure contain an equal number of molecules. Mathematically, V ∝ n (where V is volume and n is the number of molecules/moles), at constant T and P.

(OR)

i) In what way hygroscopic substances differ from deliquescent substances. ii) Uses of copper.

i) Difference between Hygroscopic and Deliquescent Substances:

Hygroscopic Substances	Deliquescent Substances
They absorb moisture from the atmosphere when exposed to it.	They absorb enough moisture from the atmosphere to dissolve in it and form a solution.
They do not change their physical state (they remain solid).	They change their physical state from solid to liquid/solution.
All deliquescent substances are hygroscopic.	All hygroscopic substances are not deliquescent.
Example: Concentrated Sulphuric acid (H₂SO₄), quicklime (CaO), silica gel.	Example: Calcium chloride (CaCl₂), Sodium hydroxide (NaOH), Ferric chloride (FeCl₃).

ii) Uses of Copper:

It is extensively used for making electrical wires and cables due to its high electrical conductivity.
It is used for making utensils, containers, and calorimeters because of its good thermal conductivity.
It is used in electroplating and electrotyping.
It is alloyed with other metals to make important alloys like brass (with zinc) and bronze (with tin).

35) i) Differentiate between systole and diastole. ii) Write a neat labelled diagram, explain the structure of a neuron.

i) Differentiate between Systole and Diastole:

Systole	Diastole
It is the contraction phase of the heart chambers (atria and ventricles).	It is the relaxation phase of the heart chambers.
During systole, blood is pumped out of the chambers.	During diastole, the chambers fill with blood.
Ventricular systole causes the 'lub' sound of the heartbeat.	Ventricular diastole causes the 'dub' sound of the heartbeat.
It corresponds to the higher pressure value in a blood pressure reading (e.g., 120 mmHg).	It corresponds to the lower pressure value in a blood pressure reading (e.g., 80 mmHg).

ii) Structure of a Neuron (Nerve Cell):

(A neat labelled diagram of a neuron should be drawn by the student).

A neuron is the structural and functional unit of the nervous system. It consists of three main parts:

Cyton (Cell Body or Soma): This is the main part of the neuron. It has a large nucleus and cytoplasm containing characteristic granules called Nissl's granules. The cytoplasm also contains other organelles like mitochondria.
Dendrites: These are short, branched processes that arise from the cyton. They receive signals or nerve impulses from other neurons and transmit them towards the cyton.
Axon: This is a single, long, cylindrical process that arises from the cyton. It conducts nerve impulses away from the cell body to other neurons or effector organs (like muscles or glands). The axon is covered by a protective sheath called the myelin sheath (in myelinated neurons), which is formed by Schwann cells. The myelin sheath has gaps called Nodes of Ranvier, which help in the rapid transmission of impulses (saltatory conduction). The axon terminates in fine branches called axon terminals, which end in synaptic knobs.

(OR)

How is the structure of DNA organised? What is the biological significance of DNA?

Structure of DNA (Watson and Crick Model):

The structure of DNA is a double helix, resembling a twisted ladder. The key features are:

Two Polynucleotide Chains: DNA consists of two long chains of nucleotides that are coiled around a central axis to form a right-handed double helix.
Sugar-Phosphate Backbone: The sides of the "ladder" are made of alternating sugar (deoxyribose) and phosphate groups, linked by phosphodiester bonds.
Nitrogenous Bases: The "rungs" of the ladder are formed by pairs of nitrogenous bases. There are four bases: Adenine (A), Guanine (G) (which are purines), and Cytosine (C), Thymine (T) (which are pyrimidines).
Complementary Base Pairing: The bases pair in a specific way due to hydrogen bonds. Adenine always pairs with Thymine (A=T) with two hydrogen bonds, and Guanine always pairs with Cytosine (G≡C) with three hydrogen bonds. This is known as the principle of complementarity.
Antiparallel Strands: The two strands of DNA run in opposite directions. One strand runs from 5' to 3' direction, and the other runs from 3' to 5' direction. This is called antiparallel orientation.

Biological Significance of DNA:

Hereditary Information: DNA is the genetic material that carries all the hereditary information from one generation to the next.
Control of Metabolism: It controls all the metabolic activities of the cell by directing the synthesis of specific proteins and enzymes.
Replication: DNA has the unique ability to replicate itself, ensuring that genetic information is passed on accurately during cell division.
Variation: Changes in the DNA sequence (mutations) are the basis of variation, which is essential for evolution.